1. Field of the Invention
The present invention relates to a leak resistant facility for storing hazardous material. More specifically, the invention relates to a storage containment structure for hazardous or other waste which is located on piles or the like, some distance above the surface of the earth to expose the lower surface of the base and the drainage system.
2. Description of the Prior Art
A number of storage facilities for hazardous wastes have been utilized in the past few decades, especially since the dangers associated with the storage of waste have become more well known. A large percentage of waste is stored underground, in containers ranging from metal and plastic barrels to specially constructed cubicles and abandoned mines. It has become increasingly recognized that at grade storage of waste allows for more careful monitoring of the facility after the waste has been loaded to prevent damage to the environment in the case of leakage.
The prior art relating to this invention is best characterized by Hillier, et al., U.S. Pat. No. 4,464,081, issued Aug. 7, 1984. The device disclosed in the Hillier patent is an above-ground facility which rests on the earth surface. The building comprises a base, walls and a cap. The inner portion of the building has successive layers of an impervious membrane, separated by a pervious layer which allows the passage of liquids therethrough. Water or other liquids which may enter the hazardous waste from the outside, or liquids leaching out of the waste itself are retained by the impervious membranes. If a break should occur, liquid passing through a membrane would enter the pervious layer, and be transported via gravity to the lowest point in the system. A drainage system, provided at the lowest point of each layer, allows the liquid to be drained off and tested. In this way, monitoring of the leachate is utilized to detect leaks and contamination of the system.
This system, while very effective in detecting and retaining leaks in the membrane system, is limited in its ability to detect leaks or blockages in the membrane system at the base of the facility, in the base itself or those portions of the drainage system which reside inside the facility. Additionally, at grade storage in low lying or tidal areas presents a serious environmental risk in the event of a flood or an exceptionally high tide condition. Water which envelops the containment structure is much more likely to leak into the structure and create an uncontrollable effluent of hazardous liquid.
There remains, therefore, a need in the art for a facility which allows for the leak resistant storage of hazardous and other waste and the detection of leaks in the retention system, and which also allows visual examination and physical inspection of the entire facility and the entire drainage system. Additionally, such a facility should be adapted to resist flood waters and high water table conditions in low lying areas.